scholarly journals X-ray spectroscopy of the starburst feedback in 30 Doradus

2021 ◽  
Vol 504 (2) ◽  
pp. 1627-1643
Author(s):  
Yingjie Cheng ◽  
Q Daniel Wang ◽  
Seunghwan Lim
Keyword(s):  
Ambient Medium ◽  
Emission Measure ◽  
Chemical Properties ◽  
Cosmic Ray ◽  
H Ii Regions ◽  
X Ray ◽  
Spatially Resolved ◽  
Hot Plasma ◽  
Spatially Resolved Spectroscopy ◽  
30 Doradus

ABSTRACT X-ray observations provide a potentially powerful tool to study starburst feedback. The analysis and interpretation of such observations remain challenging, however, due to various complications, including the non-isothermality of the diffuse hot plasma and the inhomogeneity of the foreground absorption. We here illustrate such complications and a way to mitigate their effects by presenting an X-ray spectroscopy of the 30 Doradus nebula in the Large Magellanic Clouds, based on a 100 ks Suzaku observation. We measure the thermal and chemical properties of the hot plasma and quantitatively confront them with the feedback expected from embedded massive stars. We find that our spatially resolved measurements can be well reproduced by a global modelling of the nebula with a lognormal temperature distribution of the plasma emission measure and a lognormal foreground absorption distribution. The metal abundances and total mass of the plasma are consistent with the chemically enriched mass ejection expected from the central OB association and a $\sim 55{{\ \rm per\ cent}}$ mass-loading from the ambient medium. The total thermal energy of the plasma is smaller than what is expected from a simple superbubble model, demonstrating that important channels of energy loss are not accounted for. Our analysis indeed shows tentative evidence for a diffuse non-thermal X-ray component, indicating that cosmic ray acceleration needs to be considered in such a young starburst region. Finally, we suggest that the lognormal modelling may be suitable for the X-ray spectral analysis of other giant H ii regions, especially when spatially resolved spectroscopy is not practical.

scholarly journals Probing the effects of hadronic acceleration at the SN 1006 shock front

2013 ◽  
Vol 9 (S296) ◽  
pp. 315-319
Author(s):  
Marco Miceli ◽  
F. Bocchino ◽  
A. Decourchelle ◽  
G. Maurin ◽  
J. Vink ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Spectral Analysis ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Ambient Medium ◽  
Cosmic Ray ◽  
X Ray ◽  
Spatially Resolved ◽  
Large Program ◽  
Post Shock

AbstractSupernova remnant shocks are strong candidates for being the source of energetic cosmic rays and hadron acceleration is expected to increase the shock compression ratio, providing higher post-shock densities. We exploited the deep observations of the XMM-Newton Large Program on SN 1006 to verify this prediction. Spatially resolved spectral analysis led us to detect X-ray emission from the shocked ambient medium in SN 1006 and to find that its density significantly increases in regions where particle acceleration is efficient. Our results provide evidence for the effects of acceleration of cosmic ray hadrons on the post-shock plasma in supernova remnants.

Ultralow-Energy Excitations and Prospects for Spatially Resolved Spectroscopy

2004 ◽  
Vol 10 (1) ◽  
pp. 28-33 ◽  
Author(s):  
A. Howie
Keyword(s):  
Electric Fields ◽  
Electron Beams ◽  
Condensed Matter ◽  
Intermediate Energy ◽  
X Ray ◽  
Ultralow Energy ◽  
Spatially Resolved ◽  
Direct Excitation ◽  
Spatially Resolved Spectroscopy ◽  
Electron Energy Loss

The key contribution of electron microscopy methods to condensed matter spectroscopy is undoubtedly spatial resolution. So far this has mainly been manifest through electron energy loss spectroscopy in the 1-eV to 10-keV energy range and has not seriously challenged the dominance of optical, X-ray, and neutron spectroscopy methods over most of the vast field at lower energies. At frequencies up to a few megahertz, corresponding to energies of a few nanoelectron volts and below, direct excitation by pulsed electron beams or electric fields has proved effective. Prospects are discussed for extending spatially resolved spectroscopy to the intermediate energy region, mainly by combining the advantages of electrons with those of photons.

Searching Ultimate Nanometrology for AlOx Thickness in Magnetic Tunnel Junction by Analytical Electron Microscopy and X-ray Reflectometry

2005 ◽  
Vol 11 (5) ◽  
pp. 431-445 ◽  
Author(s):  
Se Ahn Song ◽  
Tatsumi Hirano ◽  
Jong Bong Park ◽  
Kazutoshi Kaji ◽  
Ki Hong Kim ◽  
...  
Keyword(s):  
Line Profile ◽  
Analytical Electron Microscopy ◽  
Random Access ◽  
Chemical Properties ◽  
Magnetic Tunnel Junction ◽  
Chromatic Aberration ◽  
Time Resolved ◽  
X Ray ◽  
Spatially Resolved ◽  
Beam Damage

Practical analyses of the structures of ultrathin multilayers in tunneling magneto resistance (TMR) and Magnetic Random Access Memory (MRAM) devices have been a challenging task because layers are very thin, just 1–2 nm thick. Particularly, the thinness (∼1 nm) and chemical properties of the AlOx barrier layer are critical to its magnetic tunneling property. We focused on evaluating the current TEM analytical methods by measuring the thickness and composition of an AlOx layer using several TEM instruments, that is, a round robin test, and cross-checked the thickness results with an X-ray reflectometry (XRR) method. The thickness measured by using HRTEM, HAADF-STEM, and zero-loss images was 1.1 nm, which agreed with the results from the XRR method. On the other hand, TEM-EELS measurements showed 1.8 nm for an oxygen 2D-EELS image and 3.0 nm for an oxygen spatially resolved EELS image, whereas the STEM-EDS line profile showed 2.5 nm in thickness. However, after improving the TEM-EELS measurements by acquiring time-resolved images, the measured thickness of the AlOx layer was improved from 1.8 nm to 1.4 nm for the oxygen 2D-EELS image and from 3.0 nm to 2.0 nm for the spatially resolved EELS image, respectively. Also the observed thickness from the EDS line profile was improved to 1.4 nm after more careful optimization of the experimental parameters. We found that EELS and EDS of one-dimensional line scans or two-dimensional elemental mapping gave a larger AlOx thickness even though much care was taken. The reasons for larger measured values can be found from several factors such as sample drift, beam damage, probe size, beam delocalization, and multiple scattering for the EDS images, and chromatic aberration, diffraction limit due to the aperture, delocalization, alignment between layered direction in samples, and energy dispersion direction in the EELS instrument for EELS images. In the case of STEM-EDS mapping with focused nanoprobes, it is always necessary to reduce beam damage and sample drift while trying to maintain the signal-to-noise (S/N) ratio as high as possible. Also we confirmed that the time-resolved TEM-EELS acquisition technique improves S/N ratios of elemental maps without blurring the images.

Deep Chandra observations of the core of the Perseus cluster

2018 ◽  
Vol 14 (S342) ◽  
pp. 127-132
Author(s):  
Jeremy S. Sanders
Keyword(s):  
Spatial Scales ◽  
High Quality ◽  
X Ray ◽  
The Core ◽  
Spatially Resolved ◽  
Spatially Resolved Spectroscopy ◽  
Perseus Cluster ◽  
Metallicity Distribution

AbstractThe Perseus cluster is the X-ray brightest cluster in the sky and with deep Chandra observations we are able to map its central structure on very short spatial scales. In addition, the high quality of X-ray data allows detailed spatially-resolved spectroscopy. In this paper I review what these deep observations have told us about AGN feedback in clusters, sloshing and instabilities, and the metallicity distribution.

scholarly journals Chandra and XMM Observations of Galaxy Groups: The Influence of Central AGN at the Low End of the Cluster Mass Scale

2006 ◽  
Vol 2 (S235) ◽  
pp. 255-255
Author(s):  
J. M. Vrtilek ◽  
E. J. O'Sullivan ◽  
L. P. David
Keyword(s):  
Angular Resolution ◽  
Mass Scale ◽  
Heavy Elements ◽  
High Angular Resolution ◽  
Galaxy Interactions ◽  
X Ray ◽  
Galaxy Groups ◽  
Spatially Resolved ◽  
Formation And Evolution ◽  
Spatially Resolved Spectroscopy

AbstractChandra and XMM, offering between them high angular resolution, substantial collecting area, and spatially-resolved spectroscopy at good spectral resolution, have given us the means to discover hitherto unanticipated phenomena, in groups as in clusters, and to explore a new set of issues that bring us closer to understanding the formation and evolution of groups and their constituent galaxies: the distribution of heavy elements, the presence of X-ray cavities and their relation to radio observations, the nature of cooling cores, and X-ray signatures of recent galaxy interactions. We here show Chandra and XMM data selected to illustrate recent results regarding some of these themes.

scholarly journals Absolute soft x-ray measurements with a transmission grating spectrometer

1986 ◽  
Vol 4 (3-4) ◽  
pp. 521-530 ◽  
Author(s):  
K. Eidmann ◽  
T. Kishimoto ◽  
P. Herrmann ◽  
J. Mizui ◽  
R. Pakula ◽  
...  
Keyword(s):  
Laser Plasma ◽  
X Ray ◽  
Transmission Grating ◽  
Grating Spectrometer ◽  
Spatially Resolved ◽  
Laser Plasmas ◽  
Spatially Resolved Spectroscopy ◽  
Absolute Measurements

Absolute measurements of the soft x-ray emission (50 eV < hv < 1000 eV) from laser plasmas were made with transmission gratings, including pinhole-grating combinations for spatially resolved spectroscopy. Kodak 101–01 film was absolutely calibrated as a function of wavelength with the help of a bolometer, the laser plasma being used as a source. An example of a quantitatively analyzed, space-resolved pinhole grating spectrum recorded on film will be shown.

scholarly journals X-ray Studies of the Pulsar Wind Nebula Around PSR B0540-69

2004 ◽  
Vol 218 ◽  
pp. 189-192
Author(s):  
R. Petre ◽  
U. Hwang ◽  
S. S. Holt ◽  
R. M. Williams
Keyword(s):  
Particle Flux ◽  
Crab Nebula ◽  
Large Magellanic Cloud ◽  
Thermal Component ◽  
X Ray ◽  
Average Ratio ◽  
Spatially Resolved ◽  
Pulsar Wind ◽  
Spatially Resolved Spectroscopy ◽  
The Crab Nebula

The pulsar wind nebula (PWN) surrounding the 50-ms pulsar B0540-69 in the Large Magellanic Cloud shares many properties with the Crab Nebula, the canonical Galactic PWN. We have used the ACIS instrument on the Chandra X-ray Observatory to perform spatially resolved spectroscopy of the PWN. The spectrum of the inner 10″ is characterized by a simple power law, with a spectral index that steepens strongly with radius. Outside the central 10″ the spectra also require a thermal component. This diameter corresponds to a shell detected in [OIII], suggesting that this shell represents a skin around the PWN, in analogy to the Crab. We infer the value of several key PWN parameters, including σ, the average ratio of electromagnetic to particle flux.

scholarly journals SPATIALLY RESOLVED SPECTROSCOPY OF A BALMER-DOMINATED SHOCK IN THE CYGNUS LOOP: AN EXTREMELY THIN COSMIC-RAY PRECURSOR?

2016 ◽  
Vol 819 (2) ◽  
pp. L32 ◽  
Author(s):  
Satoru Katsuda ◽  
Keiichi Maeda ◽  
Yutaka Ohira ◽  
Yoichi Yatsu ◽  
Koji Mori ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Cygnus Loop ◽  
Spatially Resolved ◽  
Spatially Resolved Spectroscopy

A New View of the LHB and ¼ keV X-ray Halo

1997 ◽  
Vol 166 ◽  
pp. 103-112
Author(s):  
S.L. Snowden
Keyword(s):  
Column Density ◽  
Galactic Disk ◽  
Emission Measure ◽  
Diffuse Emission ◽  
X Ray ◽  
Considerable Success ◽  
Hot Plasma ◽  
Sky Survey ◽  
Local Emission ◽  
Neutral Material

AbstractThe X-ray sky at ¼ keV is completely dominated by diffuse emission. It has become clear that it originates as at least three separate components: local emission within the nearest ~ 100 pc from the Sun, halo emission from beyond most of the neutral material of the Galactic disk, and the superposition of unresolved extragalactic sources. The only way to determine the temperatures and relative emission measures of the hot plasma responsible for the Galactic components is to use the X-ray intensity variations due to column density variations in the intervening Hi to separate the components. “Shadowing” studies have been pursued for individual objects using ROSAT data, from both pointed observations and the all-sky survey with considerable success.This paper presents the results of an all-sky analysis of the ¼ keV background from the ROSAT survey. A Local Hot Bubble is found consistent with, although somewhat smaller than, previous models. It has a temperature of 106.1 K and an emission measure which varies by a factor of ~ 3.3 over large angles. The halo emission has a temperature near 106.0 K with an emission measure which varies from near zero to more than five times that of the local emission.

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